Abstract 3166: Lipid nanoparticles as an efficient transfection method for the delivery of elephant TP53 and retrogene9 into osteosarcoma cells

Abstract Lipid nanoparticles (LNPs) continue to be at the forefront of nanotechnology research due to their versatile and effective ability to deliver DNA, RNA, and small molecules through the cell membrane. Since LNPs are formulated with lipids found naturally in cells, they generate a lower risk for immunogenic response and cause significantly less cell death than traditional transfection methods, such as electroporation. Our microfluidics assembled LNPs have shown transfection efficiencies over 80%, substantially higher than observed with other transfection techniques, and continues to increase over the first 72 hours. We previously reported that elephant TP53 (EP53) induces apoptosis in cancer cells at higher rates than human TP53 (huTP53), and elephant TP53 RETROGENE9 (EP53-R9) contributes to apoptosis through transcription independent mechanisms. To further characterize the effectiveness of these genes, osteosarcoma cell lines were transfected with huTP53, EP53, and EP53-R9 nanoplasmid and mRNA loaded LNPs. Cells treated with EP53 and huTP53 nanoplasmid-loaded LNPs had significantly increased caspase activity and cell death compared to those treated with the empty vector control (P<.0001), with over 90% of all cells treated with either type of p53 dead after 72 hours. Immunocytochemistry was performed to image cells using confocal microscopy, which showed a 36-fold increase in TP53 signal in the nucleus of nanoplasmid LNP treated cells after 72 hours as compared to untreated osteosarcoma cells. In contrast, cells treated with the mRNA LNPs had a 7-fold increase in TP53 signal over 72 hours, though the transfection efficiency was equivalent to the nanoplasmid treated cells. Future studies will assess the efficacy of EP53 and EP53-R9 LNPs in vivo in osteosarcoma mouse models. These results demonstrate the potential of LNP mediated delivery of EP53 and EP53-R9 to be developed as a new treatment approach for cancer patients. Citation Format: Madison Sanborn, Aaron Rogers, Gareth Mitchell, Ryan Kennington, Miranda Sharp, Joshua D. Schiffman, Lisa M. Abegglen. Lipid nanoparticles as an efficient transfection method for the delivery of elephant TP53 and retrogene9 into osteosarcoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3166.